A superscalar processing system includes multiple execution units for simultaneously executing multiple instructions. In some .processing systems, instructions are executable out-of-order relative to their programmed sequence within the instruction stream. Nevertheless, some of these processing systems are designed to write instructions' results to storage locations (e.g. architectural registers) in-order of the instructions's programmed sequence. According to typical previous techniques, such in-order writeback adversely impacts the time for instructions to be completed by the processing system.
Thus, a need has arisen for a processing system and method of operation, in which in-order writeback less adversely impacts the time for instructions to be completed by the processing system.